A&O Shearman is holding its departing partners to longer notice periods than it has previously enforced, according to six people with knowledge of the matter, as the number of partner exits since its merger announcement nears 200. Before its merger with Shearman & Sterling in May 2024, legacy Allen & Overy was entitled to hold departing partners to a contractual nine-month notice period; but the practice was usually to release partners after three to four months, several sources with knowledge of the matter said. However, sources indicate that, since the merger, the firm is holding certain partners and other senior lawyers to notice periods of far longer than had historically been the case. They said that while it used to be around three-to-four months on the legacy A&O side and around one month on the legacy Shearman side, some partners are now expecting to have to wait for several months more, and others indicate that the firm has not informed them of the exact length of the notice period they are required to see out, marking what sources described as a tougher stance on departures. One person with knowledge of the firm said the notice period is dealt with on a case by case basis, and is determined by client need, regulatory considerations and transition processes, which can be influenced by a partner’s book of business. The reports follow the firm’s loss of around 190 partners since the merger announcement in May 2023, according to Law.com analysis. The research shows that the firm has seen 157 partner departures since May 1, 2024. As the firm had around 800 partners at the time, those departures represent around 20% of the firm's partnership. In September 2024, the firm signaled plans to cut 10% of its equity partnership as part of the merger. The firm has also made 30 lateral hires since May 2024, as well as internal promotions. One insider interpreted the stricter approach to notice periods as a defensive move intended to slow departures and deter others from resigning, and said the delays are frustrating partners as well as managing partners at the firms they are joining. Another person offered a more sympathetic view of the leadership’s calculation, describing it as a "defensive measure during a sensitive period." "They’re trying to protect the business interests of the firm," the person said. "But they also have to think about what this play is costing them." Two people with knowledge of the firm said that several factors determine the terms on which a departing partner leaves and that it would stand to reason for a firm to make use of its notice period provisions where appropriate. They said they did not believe there had been any conscious firm-wide decision to extend notice periods, though one of the people conceded that, given the scale of current exits, partners overseeing individual departure processes may be more inclined to use the tool in each case. The other added that departure terms are "usually mutually agreed," and suggested that any correlation between recent departure and the longer notice periods is coincidental. Examples of recent leavers include real estate partners David Oppenheimer, David Varne, and Lucy Oddy, who are set to join Latham & Watkins in London. Corporate partner Carmelo Gordian is joining Holland & Knight in Austin while Sultan Almasoud, an M&A and capital markets partner, is moving to Morgan Lewis & Bockius. Meanwhile, employment partner Robbie Sinclair is joining Gibson Dunn & Crutcher in London announced in November 2025. Mark Manson Barr and Hayden Cameron also joined the firm in 2025. A small snapshot of the nearly 200 departures from A&O Shearman reveals the global scale of the departures. For example, since the merger, corporate partner Alexandre Rudoni moved to Hogan Lovells in Paris; Luxembourg funds partner Yannick Arbaut joined Simpson Thacher & Bartlett; Washington arbitration partner Claire Rajan went to Steptoe; and Hong Kong corporate partner Kung-Wei Liu moved to Tongshang Hong Kong. In Singapore, corporate partner Tim Beech joined Reed Smith; antitrust partner Ben Gris in Washington moved to Paul Weiss Rifkind Wharton & Garrison; and New York private equity partner Christopher Zochowski joined Paul Hastings. However, the firm has also made several hires in that period. Among them are private equity partners Dan Graham and Paul Dunbar from Sidley Austin; Severina Käppeli and Kristof Meynaerts in funds and private capital in Luxembourg, Diego Esposito in leveraged finance in Milan, Parisa Clovis in fund finance from Kirkland & Ellis; and Paul Astolfi and Katy McNeil in energy and infrastructure in the U.S. from Mayer Brown. The firm also rehired M&A partner George Knighton from Skadden, Arps, Slate, Meagher & Flom six years after he departed. Oscar Glyn and Paul Hodkinson contributed to this story.